Following with the considerably increasing number of the various vehicles produced and marketed, the usage quantity of the windshield wiper is tremendously increased. To regularly replacing the windshield wiper for the safe purpose becomes one of the necessary routine jobs that also makes the consuming quantity of the windshield wiper relatively increase. However, different vehicle model has different superficial area of the windshield, so the length requirement of the windshield wiper is different from vehicle to vehicle. How to produce various windshield wipers in different lengths and specifications in effective and economical manufacturing process becomes the critical task and challenges to the businessmen of the windshield wiper. Accordingly, the structure of the windshield wiper is constantly changed and continuously improved. For examples, the U.S. Pat. No. 7,254,862 and application published cases in numbers of US2006/0090282 and US2006/0179597 are the examples of prior arts in the related technical field. By carefully studying the technical disclosure for such cases aforesaid, the primary task is to provide various windshield wipers for different vehicles having feature in even pressure distribution over the windshield with firm and close attachment other than the declaration of double benefit in simplifying structure and reducing manufacturing cost.
However, it is generally well known that the superficial area of the windshield for sedan, recreational vehicle, van and truck is different from vehicle to vehicle. Therefore, the length and curvature of the windshield wiper must be different in accordance with the different requirement of each type of vehicle so as to have effective scraping and wiping function of the windshield wiper. In other words, the larger superficial area of the windshield is the longer of the windshield wiper needs. For certain length of the specific windshield wiper aforesaid, it may have effective scraping and wiping function for various windshield wipers of different curvatures but can not meet the requirement for various windshield wipers of the different lengths. Thus, for another length of the specific windshield wiper aforesaid, all the related components should be additionally re-produced accordingly. Therefore, the production for design of the windshield wiper aforesaid must prepare tremendously various relevant components in stock to meet the manufacturing requirements of various windshield wipers in different lengths and specifications, which will inevitably results in laborious inventory control and strenuous production management accordingly. Basing on the 20 years of experience in manufacturing windshield wipers, the applicant of the present invention is fully aware that the design of the windshield wiper aforesaid can not actually achieve the declared benefit of reducing manufacturing cost essentially.